Colours with Kalyani- Part 5

We talked about colours from Nature, used as dyes for fabrics and Yarns.  All these colours require some elements to fix the dyes  on to the fabric.  Today we shall talk about Mordants.  The beauty of plant dyeing is that there are so many methods for producing colour on yarn and fabric.
Most plants produce some kind of colour, but it is certainly true that some plants make better dyes than others.

What are Mordants and how does one use them?
A Mordant or dye fixative is a substance used to set, that is, bind dyes on fabrics by forming a coordination complex dye, which then attaches to the fabric or yarn.
Basically Mordants allow the dye to chemically bind to the fabric.  You can add mordant to the fabric before you dye it or add it to the dye pot.  Mordants such as copper and iron will also alter the colour of the dye.

Just an example: one batch of Marigold dye stuff can dye a fabric/ yarn to a yellow.  Then after adding the right amount of iron to the dye bath, you can get olive green.
Some dye stuffs (avocados, onion skins, and black walnuts) contain tannins, which act as mordants. This means you can skip this step altogether unless you want to change the color.

Alum is one of the easier mordants to use and should always be added to a cup of warm water to dissolve before being added to a dye pot. Pairing it with cream of tartar can help brighten the overall color.
Copper is usually used to dull or darken your colors. Iron can also darken and change the colors. Use it to get greens, greys, or browns.
White vinegar is used to brighten turmeric dye- it changes it from a bold orange to a bold yellow.
All fibers should be scoured prior to dyeing for the best results. Scouring is the process of removing oils or chemicals occurring in nature or through the manufacturing process. You can scour linen and cotton using hot water.

Getting started:
Step One: Wash fabric in the washing machine with a pH neutral detergent in warm to hot water or heat it in a pot of water and unscented dish soap until it’s boiling. Simmer for an hour and let cool. Rinse with cool water. Add it while it’s wet to the empty dye pot.
Step Two: Prepare the dye pot by filling the stainless steel pot with enough cool, filtered water to cover fabric. Add the dye stuffs to the pot and bring it to a simmer. Should not  boil as it will muddle the color. Let it simmer for 45-60 minutes before turning off the heat and letting it cool. The longer you leavee the fabric in the dye pot, the stronger the color may become. The color you see when wet may be slightly darker than the color of the fabric when dry.
Step Three: Let the fabric air dry in a shady spot before rinsing it in cool water. Feel free to wash and dry as usual.
There’s something intrinsically special about using plants to dye own fabric. It connects us to the process of designing our own clothes and home goods in a way that gives us more respect and curiosity for the materials used and the process itself.

Alum (potassium aluminum sulfate) is the most common mordant. If you are not sure what you want to do, mordant with alum, and use the others as additives. Alum does not affect color. It is usually used with cream of tartar, which helps evenness and brightens slightly.

Iron (ferrous sulfate) is called copperas. It will sadden or darken colors, bringing out green shades. Usually cotton and wool is dyed before mordanting with iron when darker shades are required. Simmering dye‐bath for ½ hour, too much iron will harden wool and make it streak.

Tin (stannous chloride) blooms or brightens colors, especially reds, oranges and yellows. Almost always used with cream of tartar —Simmering for an hour and rinse in soapy water before dyeing. Tin is a good additive mordant. Too much tin makes wool brittle. It is caustic, be sure to handle carefully and clean up thoroughly.

Blue vitriol (copper sulfate) saddens colors and brings out greens. It is a good additive used alone.

Hope you can use this information and start your dyeing explorations.
Write to us at to discuss more and share your experiences.


Earlier episodes of 'Colours with Kalyani':

Part 4: Dyeing with Natural dyes: part 1

Part 3: Colours in Poetry & Literature

Part 2: Colours & birds

Part 1: Colours in nature

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